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The team of two men and two women climbed through windows of an observation deck and a hatch near the top of the 555-foot monument to start their work shortly after noon. They used ropes and harnesses to climb up and then slowly rappel down the uppermost portion known as the pyramidion, where they expect to find the most damage. A large crack was previously spotted there.

With small cameras, masonry, climbing tools and iPads, their job was to document the condition of the stones on the pyramid at the top of the monument.

The four could be seen crouching, moving side-to-side and making small movements up or down the face of the obelisk's top section.

Senior climber David Meggerly spent Tuesday securing the ropes that climbers used Wednesday. “He says he's not crazy, he loves doing what he does… and he had a good time up there,” said Carol Johnson of the National Mall and memorial parks.

In the coming days, the team will climb up and down the entire monument to check each stone for cracks, chips and other damage caused by the 5.8-magnitude quake that shook the nation's capital Aug. 23. They will take breaks as needed by making a descent that can take 12 to 15 minutes without stops, and resume work by riding the elevator back to the top.

Each team member is carrying several items, including a digital camera, an iPad that includes data from the 1999 restoration of the monument, a two-way radio, masonry tools that will allow them to remove loose pieces of stone or mortar and a soft mallet for audio testing. They will tap on the stones with the mallet and listen for indications of structural problems.

Deb Blanchard drove to Washington on Wednesday morning from her home in Palmyra, Penn., to watch her brother, Erik Sohn, scale the face of the monument. Blanchard said she was nervous watching Sohn emerge from the window.

"This doesn't make me feel very good right now. I've got to be honest about that. Wow," said the 39-year-old Blanchard, adding that her brother wasn't nervous.

"He's a very responsible, meticulous, careful kind of person. This fits his personality," Blanchard said. "It's such a fantastic opportunity for him."

Sohn is part of a team from a private firm that's certified with a rare combination of climbing and engineering skills.

They are in frequent contact with the National Weather Service and will suspend work on the monument's exterior if there's a chance of lightning or heavy winds. The weather was calm and mostly cloudy late Wednesday morning after an earlier thunderstorm and showers.

Tyrone Beasley and his family were in town from Harrisburgh, Pa., to see the climb. Everywhere on the Mall, people looked up and pulled out their cameras.

“I've been going around the city taking pictures of earthquake damage and I thought, well I'll d take the segway and my 300 millimeter lens and see what I can do,” said Ron Barry.

The inspection of the monument's exterior was delayed a day because of lightning. A team worked for several hours Tuesday setting up equipment and creating a protective barrier around the monument's lightning rods.

The inspection is expected to last several days and the team has not ruled out working over the weekend.